Breast cancer is usually treated with surgery and then possibly with chemotherapy or radiation, or both. There are two surgical options: mastectomy (removal of entire breast) and lumpectomy (removal of lump only). Lumpectomy is currently the most common treatment, suitable for at least 60% of women with breast cancer.
During lumpectomy, it is important to take out all cancerous tissue, in order to minimize the risk of cancer recurrence. However, surgeons avoid excision of unnecessarily large-tissue volumes, which negatively impacts cosmetic results. In order to verify that all cancerous tissue has been removed, the lump is pathologically examined in order to check if the lump's outer edges contain cancerous tissue or not (positive or negative margins). If positive margins are retrospectively detected on the lump during pathology, in many cases a repeated operation is necessary in order to take out additional tissue.
There is a significant unmet clinical need to provide breast cancer surgeons with a system that can indicate the margin status of excised breast lumps (including any additional “augmentation” pieces of breast tissue) during the surgical procedure, so that if needed, additional tissue can be excised, until all margins are indicated as negative.
PCT Patent Application PCT/US2011/023101 describes systems and methods for confirming the existence of a clean margin of healthy tissue around an excised tumor. The system includes an imaging scanner controlled by an imaging control unit and an ex-vivo sample holder for holding a sample of an excised tissue. The sample holder is sized so that excised lump edges of the excised tissue are forced against a surface of the sample holder such that the edges change shape to have a predetermined geometry. The imaging scanner is positioned relative to the sample holder such that the imaging scanner acquires images (or measurements) not of all the tissue but rather of the edges that have the predetermined geometry and which are in a sensitive region extending into a peripheral margin of the tissue.
US Patent Application 20140111202 describes a portable magnetic resonance imaging (MRI) system that spatially encodes images using spatial inhomogeneities in the static polarizing magnetic field rather than using gradient fields. The inhomogeneous static field is used to polarize, readout, and encode an image of the object. To provide spatial encoding, the magnet is rotated around the object to generate a number of differently encoded measurements.